Electronic control device
US4335376A · kind A · utility
Inventor
Key dates
| Filing date | Apr 12, 1979 |
| Grant date | Jun 15, 1982 |
| Priority date | — |
| Expiry date | Apr 12, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/08
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A security device for protecting premises having three separate variable time delays. A first time delays allows a legitimate user of the device to enter the premises and de-activate the device before the alarm sounds. The second time delay permits a legitimate user to exit from the premises without sounding the alarm. The third time delay ensures that the alarm will sound for a minimum period once the loop has been opened by an intruder. The device has an integrated circuit and each of the time delays are achieved through the use of a resistor in combination with a capacitor. The device also has a supervisory loop and the alarm becomes activated when the loop has been opened.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.